Musical instrument with audio signal to force translator



July 20, 1965 T. PERCY 3,195,389

MUSICAL INSTRUMENT WITH AUDIO SIGNAL T0 FORCE TRANSLATOR Filed May 27, 1963 V 2 Sheets-Sheet 1 Tom Percgr IN V EN TOR.

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July 20, 1965 T. PERCY MUSICAL INSTRUMENT WITH AUDIO SIGNAL TO FORCE TRANSLATOR 2 Sheets-Sheet 2 Filed May 2'7, 1963 H QMZZTIU J I I I l l l l l I I ll MHI IHHH 3 I Tom Percy INVENTOR.

United States Patent 3,195,389 MUSICAL INSTRUMENT WITH AUDIO SIGNAL T0 FORtIE TRANSLATOR Torn Percy, 663 E. 1st St., Coquiile, Oreg. Filed May 27, 1963, Ser. No. 283,208 Claims. (Cl. 84-5) This invention relates to mechanism operable to produce actuation of musical instruments operated from a keyboard, or actuation of other instruments having multiple tone producers, with actuation of the instrument being in response to audio frequency signals. More specifically the invention concerns mechanism that may be used to play a piano or organ, automatically, using a sound source such as a microphone, or a tape or record player, or similar means as the means for controlling the various notes or tones in the musical structure or composition played by the instrument.

A general object of the invention is to provide novel apparatus or means for playing an instrument, such as a piano or organ, Where the selection of tones played by the instrument is made on the basis or audio frequency signals supplied the apparatus.

Another general object is to provide a novel audio signal to force translator, which may be employed to produce automatic playing of a musical instrument such as a piano or other instrument, operated by a keyboard.

A further object is to provide apparatus, comprising the combination of a means for producing audio signals, or an audio signal source, such as a record or tape player, an audio signal to force translator connected to this source of audio signals (including plural actuators that are shifted in response to audio signals), and a musical instrument with multiple tone producers including selectively actuated means for operating said tone producers, said selectively actuated means of the instrument being operated upon by said key actuators whereby the source of audio signals produces automatic playing of the instrument.

According to this invention, a recording of an orches tral performance may be played in the apparatus, with such producing plural audio signals corresponding to the various tones making up the musical structure of the recorded performance. These audio signals are fed into a multiple channel, audio frequency selective amplifier circuit, where each channel in the circuit selectively amplifies an audio frequency signal corresponding to the pitch of one of the tones playable by a piano or organ. The audio frequency signals after selective amplification are utilized to actuate the difierent tone producers in the piano or instrument, whereby the piano plays a musical piece corresponding to the recorded performance.

Using a microphone, and further explaining the invention, a musician may play an instrument, with the microphone being operable to produce multiple audio frequency signals which are amplified in the multiple channel, audio frequency selective amplifier circuit to produce playing of an organ or piano, with such providing accompaniment for the musician.

In a specific embodiment of the invention, a bank of solenoid operated key actuators or plungers are mounted on an elongated frame, which is adapted to be placed over the keyboard of a musical instrument operated by keys. In operative position, each plunger registers with a separate key in the keyboard. The various solenoids operating the plungers are electrically connected to different channels of the multiple channel audio frequency selective amplifier circuit mentioned. A source of audio signals is electrically connected to the input of the multiple channel selective amplifier circuit.

The source of audio signals, such as a tape or record player, together with the multiple channel audio frequency selective amplifier circuit, and other electrical parts, may be mounted in a cabinet as a unit separate from the frame mounting the plungers. Alternatively, the various electrical par-ts and the plungers that actuate the instrument keys may be mounted in one cabinet, with such shaped to fit beside or on a piano with the plungers in proper registry with the piano keys.

Various novel objects and features of the invention will become more fully apparent as the following description is read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a view illustrating a piano (such being exemplary of a musical instrument operated from a keyboard) having an elongated frame or casing positioned over its keyboard mounting plungers or key actuators as contemplated, and a cabinet disposed to one side of the piano which may contain circuitry and other parts necessary to produce playing of the piano;

FIG. 2 is a block diagram illustrating a source of musical audio signals, and an audio signal to force translator connected to this source of signals, such forming a means producing playing of the piano as contemplated by the invention;

FIG. 3 is a cross sectional view taken through the keyboard of the piano in FIG. 1, and drawn on a slightly enlarged scale;

FIG. 4 is a top plan view of the keyboard in FIG. 3, this figure further illustrating the plungers or key actuators which are provided to stroke or depress the keys in the keyboard of the piano; and

FIG. 5 is a schematic illustration of portions of an electrical circuit that may be employed in the invention.

Referring now to the drawings, and first of all more particularly FIG. 1, at 10 there is indicated an upright piano, including an upright case 12, and along the front of case 12 a keyboard 14 with keys 16. Within case 12 is the usual plate found in a piano having piano strings strung thereover (not shown) which, when the strings are struck, produce the different tones of the piano. Keys 16 in keyboard 14 are connected in a conventional manner to the usual piano actions (not shown) which sound the strings .and control the dampers in the piano. In the ordinary piano there are 88 notes or tones that are playable, and thus 88 keys are provided in the keyboard for actuating the various tones.

As best illustrated in FIGS. 3 and 4, disposed over the top of keyboard 14, and extending along the length thereof, is an elongated casing or frame 20. In the embodiment of the invention shown, casing 20 includes a detachable cover 22 over the top thereof which may be removed to allow access to the interior of the casing. Integral with the ends of casing 20 are a pair of blocks 24. These are employed in mounting the casing in a fixed position over the top of the keyboard. Thus, blocks 24 are shown secured by clamps 28 to key blocks 26 at either end of the keyboard. If desired, a pad, such as pad 36, may be provided between each block 24 and the key block thereunder to absorb vibration, to protect the top of the key block, and to enable some adjustment in the spacing of the underside of casing 20 from the tops of the keys in the keyboard.

Mounted within casing 20 and distributed along the length thereof are a plurality of vertically reciprocal key actuators or plungers 32. Each plunger registers with a different key in the keyboard. Bottom ends 33 of the plungers protrude outwardly from the bottom of the casing, and when a plunger is shifted downwardly (as to the position of the plunger indicated at 32b in FIG. 3), its bottom end is operable to depress the key below to produce actuation of the piano action connected to the key.

Each plunger is shifted downwardly by means of a solenoid 36 (one of which is shown schematically in FIG. enclosed within a sleeve 33. The solenoids constitute power-operated means, more specifically electricallyoperated means, that are operable when actuated to move or shift the plungers downwardly. Each plunger is re turned to its raised position, which is the normal at rest position for the plunger, by a coil spring 40, interposed between a mounting plate :2 within the casing and top ends 34 of the plungers.

As contemplated by this invention, actuation of selected ones of the plungers, and thus selected ones of the keys, is brought about through the production of audio signals, as by using a conventional microphone, or a tape or record player. These signals are electrical frequencies, in the audio range, where the levels of the frequencies correspond to the pitches of the various audible tones that make up a complete, musical piece. Thus, the signals are referred to herein as musical audio signals.

More specifically, and referring to FIG. 1, in the embodiment of the invention showna cabinet is provided which is indicated at 5%. This cabinet may be mounted on the floor to one side of piano 10.

Within cabinet 56, as can be seen with reference to FIG. 2, there is provided a source of musical audio signals, exemplified by turntable 52 and photograph pickup 54. Also present within cabinet 56 is a conventional amplifier circuit, indicated by the block 56 which electrically amplifies the audio signals fed thereto from pickup 54 through conductors 57, 58. Amplified audio signals emanating from amplifier circuit 56 are fed into the input of a multiple channel audio frequency selective amplifier circuit, represented by block 60 in FIG. 2. Multiple channel amplifier circuit 66 selectively amplifies, in different channels within the circuit, those frequencies in the mixed frequency audio signals fed the circuit that correspond to the pitch of different tones produceable in the piano. Circuit 66 is shown in more detail in FIG. 5.

Referring to FIG. 5, from the amplifier circuit 56 shown in FIG. 2 mixed audio frequency signals are fed into selective amplifier 60 through input conductors 63, 64. Connected in parallel to. conductors 63, 64 (the input for the selective amplifier circuit) are multiple channels, each of which selectively amplifies an audio frequency signal, with rejection of other audio frequency signals which are amplified by other channels. For reasons of simplicity, only two of these selective channels are shown in FIG. 5

(identified as channel 1 and channel 2), but it should be understood that in the apparatus contemplated one channel is provided to amplify each audio signal fed into the circuit having a frequency that corresponds to the pitch of one of the tones playable by the piano.

Each channel of the audio frequency selective amplifier comprises, in the embodimentillustrated, a transistorized Q-multiplier circuit. Each of these Q-multiplier circuits is series-resonant as seen from the signal source, and each amplifies the resonant frequency to which it is tuned, while effectively shunting this frequency from the other tuned channels.

Describing one of the channels generally, and consida and de-energizing of solenoid 36 operating a plunger or key actuator. V

In stage 66, or the Q-multiplier circuit portion of the channel, a transistor 114 is provided having its collector 114a connected through conductor 138 to a negative voltage source B (12 volts). Providing bias for base 1114b of the transistor is-a resistor 116 connected between voltage source B and the base. Input conductor 63 is 112 to base lldb of transistor T14. Input conductor 64- (ground) is connected to emitter 1114c of transistor 114 through resistor 118. Positive feedback in the multiplier circuit results from a connection provided between emitter 114s and inductor llilll through variable resistor 122. A condenser 12!) is interposed between ground (conductor 6 5) and the electrical connection between inductor ltlfi and condenser 112.

The Q-multiplier circuit described is tuned to its resonant frequency (the frequency it amplifies) by tuning inductor Mt Instability in this circuit (self-oscillation) is prevented by proper adjustment of variable resistor 122. Theelectrical frequency amplified by the stage appears between conductor 64 and conductor 123, which constitute the output of the stage. 7

The output from stage 66 is fed through a coupling condenser 124 to a transistor 136 in amplifier stage 68. C01- lector 136a of transitsor 136 is connected by conductor 137 to negative voltage source B Base 1365 is biased through resistor 134 and variable resistor 170. Rectifiers 128 and 126, between condenser 124 and the base of transistor 136, and between condenser 124 and conductor 64 (ground) function to rectify the output from transistor 114. Condenser 130 and resistor 132, connected between the base of transistor 136 and ground, constitute an R-C circuit producing a relatively constant voltage (for a given amplitude in the original signal) that is applied to the base of transistor 136 when an amplified signal is fed into stage 68. The voltage, of course, will have different levels depending upon the amplitude of the original signal fed the current. In amplifier stage'68, current flow takes place through transistor 136 during those periods that the Q-multiplier stage preceding it is operating.

Switching stage 70 is controlled by the output of amplifier 'stage- 68, and comprises a transistor 146 with the base 146a connectedfthrough resistor 144 to the output of transistor 136. The collector l46b of transistor 146 is connected through conductor 154, solenoid 36, and conductor 152 to negative voltage source B (-24 volts). Between conductors 152 and 154 is a rectifier 148. On

conduction taking place through transistor 146, current flow takes place through solenoid 36 causing the plunger or key actuator operated by solenoid 36 to. shift downwardly against a key. Rectifier 148 provides a path for the flow of current between the ends of coil 36 after periods when the coil has been energized.

Explaining the operation of the apparatus described, let it be assumed that a particular tone is picked up by the phonograph pickup, from a record placed on turntable 52. An audio frequency corresponding to the tone is amplified in amplifier circuit 56, and the amplified audio frequency signal leaving the amplifier circuit is fed into multiple channel audio frequency amplifier circuit 60. In circuit 60, the channel which is tuned to the frequency of the audio signal selectively amplifies the signal, with the other channels rejecting it. The amplified signal finally produces actuation ofva solenoid such as solenoid 36 causing a plunger or key actuator to depress a piano key and produce playing of a particular note or tone in the piano. When multiple audio frequencies are produced by the phonograph pickup, these are all amplified in circuit 56, and channels tuned to the frequencies selectively amplify the frequencies, to produce playing of multiple tones in the piano. The-larger the amplitude of the tone originally picked up by the pickup, the larger the current flow that results through transistorl4-6 and solenoid 36;, and the louder the tone finally produced in the piano. With a sustained tone a sustained current flow in solenoid'36 results, and the key operated thereby is depressed and held down over a time period to produce a sustained tone in the piano.

Obviously changes may be made in the circuits described, and in the various parts, without departing from the invention. For instance, a separate cabinet containing the pickup and amplifying parts need not be provided, but these may be mounted in a unit which includes casing as a part thereof. Such a structure, however, may be harder to adapt to different sizes and shapes of pianos than the one disclosed. Various forms of audio signal sources are contemplated, such as a microphone, or tape player, which could be substituted for the record player disclosed. An important part of the invention is that selective amplification takes place of various audio signals. While the particular circuit disclosed is found practical for this purpose, obviously other circuits could be used providing they had suitable selectivity.

The description of the invention included herein is for the purposes of illustration, and by including the description it is not intended to be limited specifically thereto, as it is desired to cover all modifications within the scope of the invention that come within the appended claims.

I claim:

1. For a musical insrument, with multiple tone producers operated from a keyboard including a separate one for each tone in an eight-tone musical octave, an audio signal to force translator comprising a multiple channel audio frequency selective amplifier circuit including a separate channel for each of said tones in said musical octave,

each of said channels in said circuit comprising means for selectively amplifying an audio frequency signal.

corresponding to the pitch of one of said eight tones in said musical octave produced by one of the tone producers in said instrument, and

means operatively connected to each of said channels operated by the amplified signal produced thereby for actuating a key in said keyboard for playing one of said eight tones.

2. For a musical instrument, with multiple tone producers including a separate one for each tone in an eighttone musical octave, and plural selectively actuated means for operating said tone producers, an audio signal to force translator comprising a multiple channel audio frequency selective amplifier circuit including a separate channel for each of said tones in said musical octave,

each of said channels comprising means for selectively amplifying an audio frequency signal corresponding to the pitch of one of said eight tones in said musical octave produced by one of the tone producers in said musical instrument, and

means operatively connected to each of said channels operated by an amplified signal produced thereby for actuating one of said selectively actuated means operating said tone producers.

3. For a musical instrument, with multiple tone producers including a separate one for each tone in an eighttone musical octave, and plural selectively actuated means for operating said tone producers,

a source of musical audio signals, and

an audio signal to force translator operatively connected to said source and operable to actuate the selectively actuated means operating said tone producers,

said translator comprising a multiple channel audio frequency selective amplifier circuit including a separate channel for each of said tones in said musical octave,

each of said channels comprising means for selectively amplifying an audio frequency signal corresponding to the pitch of one of said eight tones in said musical octave produced by one of the tone producers in the musical instrument, and

means operatively connected to each of said channels operated by the amplified signal produced thereby for actuating one of said selectively actuated means operating said tone producers.

4. For a musical instrument, with multiple tone producers operated from a keyboard including a separate one for each tone in an eight-tone musical octave,

a source of musical audio signals, and an audio signal to force translator operatively con nected to said source and operable to actuate the keys in said keyboard,

' said translator comprising a multiple channel audio frequency selective amplifier circuit including a separate channel for each of said tones in said musical octave,

each of said channels comprising means for selectively amplifying an audio frequency signal corresponding to the pitch of one of said eight tones in said musical octave produced by one of the tone producers in the musical instrument, and

means operatively connected to each of said channels operated by the amplified signal produced thereby for actuating a key in said keyboard for playing one of said eight tones.

5. For a musical instrument with multiple tone producers operated from a keyboard,

an audio frequency amplifier circuit With multiple outputs including means for selectively amplifying in different portions of said circuit selected ones of multiple audio frequency signals fed to the circuit,

said audio frequency amplifier circuit also including means producing a direct current actuating pulse in different ones of said outputs for the various audio frequency signals fed to the circuit,

said actuating pulses varying in amplitude and duration depending upon the amplitude and duration of the audio frequency signals fed to the circuit, and

means operatively connected to each of said outputs operated by an actuating pulse therein to produce actuation of a key in said keyboard.

6. The combination of a musical instrument with multiple tone producers having plural selectively actuated means for operating said tone producers,,

ing keys in a keyboard from which the tone producers are operated,

a source of musical audio signals,

an audio signal to force translator including plural key actuators,

said translator being operable to actuate selected ones of said key actuators in response to ditferent audio signals supplied thereto by said source of audio signals, and

means mounting said key actuators over said keys of said instrument.

8. The combination of a musical instrument with multiple tone producers having a keyboard with plural keys for actuating the tone producers,

a bank of plural key actuators mounted adjacent said keyboard with different ones of said key actuators registering with difierent ones of the keys in said keyboard,

power-operated means for each key actuator operable when actuated to move the key actuator whereby the same is shifted to depress a key, and

means controlling said power-operated means for the various key actuators,

said means including a multiple channel audio frequency selective amplifier circuit, 7

each of said channels in said circuit comprising means for amplfying an audio frequency signal corresponding to the pitch of a tone produced by one of the tone producers in said instrument 9. The combination of a musical instrument with multiple tone producers and a keyboard with keys connected to the tone producers for actuating the same,

a bank of plural key actuators mounted adjacent said keyboard with different ones of said actuators registering with different ones of the keys,

power-operated means for each key actuator operable when actuated to move the key actuator whereby the same is shifted to depress a key, and

means controlling said power-operated means for the various key actuators,

said last'mentioned means comprising a source of musical audio signals, and

a multiple channel audio frequency selective amplifier circuit connected to said source of musical audio signals,

each of said channels in said circuit comprising means for selectively amplifying an audio frequency signal a a bank of plurallrey 'actuators'mounted on said frame with separate ones of said actuators registering with separate ones of said keys with said frame in operative position and mounted on said instrument, electrically-operated means operatively connected to each key actuator and operable when actuated to shift the actuator with the same moving to stroke a key, and

means controlling said electrically-operated means,

said last-mentioned means comprising a source of musical audio signals,

a multiple channel audio frequency selective amplifier circuit connected to said source,

each of said channels in said circuit comprising means for selectively amplifying an audio frequency signal corresponding to the pitch of one of the tones made by a tone producer in the musical instrument and including an output for the amplified signal, and

means connecting the outputs of each of said channels to different ones of said electrically-operated means that shift the key actuators.

References Cited by the Examiner UNITED STATES PATENTS corresponding to the pitch of a tone prOduCed by Re,25,278 10/62 Borell 84l07 X one of the tone producers in said instrument. 2,912,894 11/59 H 84 171 10. Apparatus for playing a musical instrument hav- 2 924 139 2 0 Green 34 1 7 ing multiple tone producers and including a keyboa d 3 004 10 1 Wayne 34.4.01 with keys for operating said tone producers, said appara- 30 3104581 9 /63 Berwin 84 171 tus comprising an elongated frame adapted to be mounted alongside E IL P E the keyboard of sald instrument, L 0 SM nmary m 

1. FOR A MUSICAL INSRUMENT, WITH MULTIPLE TONE PRODUCERS OPERATED FROM A KEYBOARD INCLUDING A SEPARATE ONE FOR EACH TONE IN AN EIGHT-TONE MUSICAL OCTAVE, AN AUDIO SIGNAL TO FORCE TRANSLATOR COMPRISING A MULTIPLE CHANNEL AUDIO FREQUENCY SELECTIVE AMPLIFIER CIRCUIT INCLUDING A SEPARATE CHANNEL FOR EACH OF SAID TONES IN SAID MUSICAL OCTAVE, EACH OF SAID CHANNELS IN SAID CIRCUIT COMPRISING MEANS FOR SELECTIVELY AMPLIFYING AN AUDIO FREQUENCY SIGNAL CORRESPONDING TO THE PITCH OF ONE OF SAID EIGHT TONES IN SAID MUSICAL OCTAVE PRODUCED BY ONE OF THE TONE PRODUCERS IN SAID INSTRUMENT, AND MEANS OPERATIVELY CONNECTED TO EACH OF SAID CHANNELS OPERATED BY THE AMPLIFIED SIGNAL PRODUCED THEREBY FOR ACTUATING A KEY IN SAID KEYBOARD FOR PLAYING ONE OF SAID EIGHT TONES. 